Starting installation for a ski towing device

ABSTRACT

An installation for ensuring the departure sequence of skiers towed along a path defined by a continuously moving ski lift cable is provided with a plurality of tow bars which releasably engage with the ski lift cable to transport skiers up a ski slope. A mechanism is provided which automatically responds to the movement of a skier past a predetermined point for individually positioning the tow bars in releasable engagement with the moving ski lift cable whereby a skier can grasp the moving tow bar and be towed up the ski slope.

United States Patent [72] Inventor Jean Pomagalski 116 avenue de IEygala, 38 La Tronche, France 21] Appl. No. 729,117 [22] Filed May 14, I968 [45] Patented Feb. 9, 1971 [32] Priority May 19, 1967 [3 3] France [31 107.134

[54] STARTING INSTALLATION FOR A SKI TOWING DEVICE 7 Claims, 8 Drawing Figs. [52] US. Cl 104/173 [51] Int. Cl B61b 11/02 [50] Field ofSearch 43/61, 76, 99; 49/25, 28, 31,68; 119/159; 104/18, 20, 27, 30, 1 72, 1 73 1 78 [56] References Cited UNITED STATES PATENTS 922,170 5 1909 Linhardt, 10 1/30 2,874,819 2/1959 Nutter 194/9 3,183,890 5/1965 Albers..... 119/159 3,349,720 lO/l967 Pender 104/173 FOREIGN PATENTS 825,278 11/1937 France 104/173 Primary Examiner-Arthur L. La Point Assistant Examiner-Robert W. Saifer AttorneysRobert E. Burns and Emmanuel J. Lobato SHEET 1 BF 5 Wi wam em:

mg Q Q PATENTED FEB 91911 SHEET 8 [IF 5 SHEEI SUFS PATENTED tea si n.

STARTING INSTALLATION FOR A SKI TOWING DEVICE The invention relates to a device for ensuring the departure sequence of skiers towed along a path defined by a continuously driven cable of a towing installation. The towing installation includes a driven cable and a series of tow bars which are releasably engageable, on the cable and graspable by the skiers.

In pi'ior art towing installations, the departure of the skier occurs from a stop position of the skier which often imparts a violent shock to the skier owing to the inertia of the at rest skier. This shock is more or less dampened by springs or shock absorbers positioned in the T-bar. This shock sometimes throws the skier out of kilter and often causes inexperienced or beginning skiers to fall and thus delays the departure of the skiers following them.

Sometimes the person who hands the tow bar to the skier and actuates the engagement of it on the cable pushes the skier to place him in movement before he is harnessed to the cable, but this method is inefficient and requires an increased effort on the part of the towing installation attendant. Sometimes the track at the starting place of the installation is slightly sloped to facilitate the acceleration of the skier, but the initial shock imparted to the skier is not decreased since the skier nearly always is set in motionfrom a still position. Certain attendants effect engagement of the tow bar as soon as the skier is in motion, but this requires a very exact timing on the part of the attendant and such is not done systematically.

The invention has for its purpose to remedy these drawbacks by allowing the skier to be set in motion in synchronism with the engagement of the tow bar of the driven ski lift cable.

The-ski tow according to the invention is characterized by the fact that the engagement of a towing member on the cable is caused after and as a consequence of the passage of a skier at a given place in such a way that the skier, while moving, can grasp the towing member-which is already releasably engaged on the moving cable.

By making engagement of the tow bar synchronous with the positioning of the skier, all the operations can be perfectly timed and all false starts are practically avoided. The inventive device also has theadvantage of no longer requiring an attendant who must hand off the tow bars and actuate their engagement on the cable. The departure of the skiers occurs without shocks and hence it is possible to increase the operating speed of the ski tow and accordingly its rate of use.

The invention is also concerned with an installation permitting initial acceleration of the skiers characterized in that a launching slope is provided at the starting station and that a control member detects the passageof the skier at a given spot on the slope and actuates a mechanism for releasably engaging the tow bars onto the cable.

The detector for the passage of the skier as well as the transmission devices for their actuation can naturally be of any type, mechanical, electrical or hydraulic.

According to the invention, the installation comprises a closing signal for the track which indicates to the skier the moment that he can go on the launching slope.

In this manner, there is avoided the entrance of a skier on a launching track as long as the installation is not in condition to ensure a nonnal start. The operation of the assembly of the installation is thus made automatic and departures take place at high speed without loss of time. It is possible to simplify the shock absorbers or the springs of the towing members, all shocks being practically eliminated.

Other advantages and features will appear from the follow ing description of two embodiments of the invention given by way of nonlimiting examples and shown in the accompanying drawings in which:

FIG. I is a schematic perspective view of a starting station of a ski tow according to the invention showing a skier ready to engage an actuating device;

FIG. 2 is a view similar to FIG. 1 showing the skier catching a tow bar which has just become free;

FIG. 3 is a view similar to FIG. 1 showing the final phase of launching;

FIG. 4 shows, on an enlarged scale, a detail of FIG. I relating to the mechanism for releasing the tow bars;

FIGS. 5 and 6 are partial views of FIG. 4 illustrating, respectively, the blocking and the freeing of a tow bar fastener;

FIG. 7 is a view similar to FIG. I showing a modification of the invention; and

FIG. 8 shows on an enlarged scale a detail of the device of FIG. 7 concerning the mechanism for freeing the bars.

In the F IGS., an aerial driven cable 10 of a towing device for skiers or ski tow is continuously moved in the direction of arrows F by a driving device I2 fixed on a chassis 13 of a base or post 15. Traction members or tow bars l4, 14, 14', etc. are temporarily stacked on a rail 16 connected to the chassis I3 and are positioned for releasable engagement on cable 10 following a skier command signal transmitted by a mechanical link, for example by a rope or cable 18, which actuates a tow bar feeding mechanism 19 for individually feeding tow bars 14 to the driven cable 10. I

Referring more particularly to FIGS. 4 to 6, the tow bar 14 is retained at the extremity of the rail 16 by a tow bar feeding device 19 which comprises a sliding stop member 20 which cooperates with a projection 22 of a fastener means 24 on the tow bar 14. The stop member 20 is constituted by the extremity of a bar 28 passing through and slidable in a guiding orifice made in rail 16 perpendicular to the longitudinal direction thereof. A bar 30 is juxtaposed to the bar 28 and also terminates in a stop member 32 which is engaged by the sliding bar 30 on the trajectory of the fasteners 24 which are slidable on the rail 16. The extremities which are opposite the stop members 20, 32 of bars 28, 30 are curved in the opposite direction and are pivotally mounted by shafts 34, 36, respectively, at the extremities of the sole of a lever 38 having the shape of a T. The T-lever 38 is itself pivoted in the middle part of the sole on a fixed pivot 40 fastened on the rail 16 in such a way that pivotal movement of lever 38 causes the ascent and descent of the bars 28, 30 and stops 20, 32, one assuming an operating position while the other assumes an inoperative positionand vice versa (see FIGS. 5 and 6).

A similar tow bar feeding device 19' for releasably retaining the fasteners 24 is positioned on the rail 16 upstream from the tow bar feeding device 19, relative to the direction of advance or sliding of bars 14. The space between the two retaining devices 19 and I9 is sufficient to clearly separate the first tow bar 14 from the other tow bars l4, 14" etc. stacked on rail 16.-

A connecting pin 42 whose extremities pivot respectively around a shaft 44 carried by the foot of T-lever 38 and by a shaft 44' carried by lever 38', mechanically interconnects the two tow bar devices 19, 19' and synchronizes the free and retention times for the bars. At the foot of T-lever 38' is secured, ofi center relative to the axis 40, a control lever 46 to which is attached a rope 18. A traction spring 48, fixed on the one hand to a fixed projection 50 of the rail 16 and on the other hand to the foot of lever 38', urges the tow bar feeding mechanism l9, 19' towards the active position of the stop members 20, 20'. It is easy to see that during a control impulse, for example a traction-on rope 18, stops 20, 20' move downwardly thereby allowing movement of the fasteners 24, 24' in synchronism with the upward movement of the stop members; 32, 32' which moves into active position. Such tow barfeed mechanism per se are well known to those skilled in the art. It should be noted that projections 22, 22 carried by fasteners 24, 24 are inclined and that the front face of the stop members 20, 20', 32, 32' have an inclination which is conjugated in such a way that during ascent of bars 28, 28', 30, 30', they come into contact with projections 22, 22' and exert an efi'ort in the direction tending to free fastener 24, 24 and necessarily release them at a perfectly determined moment corresponding to control impulse imparted to the cord 18.

Cord 18 passes on a return pulley 52 mounted freely on the base of the post 15 and is fixed at the extremity of a rod or horizontal arm 54. The arm 54 is connected to a vertical shaft 56 pivotally mounted in a fixed support (not shown) and constituting the pivot of a portal rod or tumstile 58. The latter can be a simple horizontal bar transversely cutting the track which is defined by two gates 60, 62 whose spacing prevents the passage of several skiers abreast. The height of the gates 60, 62 will preferably be adjustable as a function of the thickness of the layer of snow and barrier 60 on the side where the skier later will grasp bar 14 is arranged as a hand rail. The assembly is arranged in such a way that the skier advancing along a skier path defined by barriers 60, 62, while possibly aiding himself with the hand rail 60, necessarily pushes the portal rod 58 which causes the pivoting of the shaft 56 and the lever 54.

Portal 58 is advantageously positioned at the end of the skier path A warning signal indicating closure of the track is provided in the skier path upstream from the portal rod 58. The warning signal comprises a horizontal bar 64 transversely barring access to the skier path and adapted to rise by pivoting around a horizontal shaft (not shown). A signal panel 66 can be secured to the bar 64. The rising and falling of bar 64 is brought about by a rope 68 passing on a return pulley 70 and secured to the arm 54 of the shaft 56 of the portal 58 in such a way that the movements of the signal bar 64 is synchronized with that of the portal rod 58. The synchronous movement ensures that the signal bar 64 is closed when the portal rod is open and vice versa. Preferably, the signal bar 64 will only open during the final phase of closure of the portal rod 58 by providing a lag in the transmission of movement.

In rest position of the apparatus, a spring 48 urges through lever 38', arm 46 and rope 18, the portal rod 58 into closing position and the signal bar 64 into open position.

At the starting station, the track is arranged in such a way as to have a first section 72 which is substantially flat and which extends near the closing signal and connects at that spot to a launching slope 74 which extends along a certain distance at least up to the place where the skier grasps the tow bar.

FIGS. 1 to 3 illustrate an embodiment of a mechanical command mechanism which can be replaced by any other mechanical, pneumatical or electrical device. An electro-optical modification of the control device is illustrated by FIGS. 7 and 8 which are, respectively, views similar to FlGS. l and 6 and in which in order to designate similar parts, the same reference numbers have been used.

The control of the tow bar feeding mechanism 19, 19' of the embodiment shown in FIG. 7 is made electrically by an electromagnet 76 whose core 78 is made integral by a pin 80 to the foot of T-lever 38 in such a way that when electromagnet 76 is energized, the lever 38 pivots against a spring 48 in the position corresponding to the withdrawal of the stop member 20 and to the exit of the stop member 32. Electromagnet 76 is connected to a feed box 82 which, since it does not form part of the present invention, will not be described in detail. Portal rod 58, according to FIG. 1 detecting the passage of the skier, is replaced by an optical barrier having a luminous or invisible ray 84 which cuts the track and falls on a photoelectric cell 86. The assembly is arranged in such a way that during passage of the skier, the luminous ray is intercepted and cell 86 at that moment generates and sends an electric signal through box 82 to electromagnet 76. The signal indicating closure of the track will preferably be electro-optical, for example, with green and red traffic signals 88 commanded synchronously as a function of the interception of the luminous ray 84 in a manner well known to those skilled in the art. The launching device functions in the following manner:

The skier wishing to take the ski lift goes along the skier path in the corridor between barriers 60, 62. In case of a crowd, the skiers will line up on the waiting platform at level 72 and will go in one after the other in turn in the corridor, barriers 60, 62 preventing a simultaneous passage of two skiers abreast. As soon as thesignal indicating closing of the track is removed by raising of the bar 64 of the appearance of a green light, the skier engages on launching slope 74 by helping himself or by eventually giving himself a push by bearing on the hand rail 60 (see FIG. 1). He will have taken the precaution of carrying his poles in the other hand. The skier then slides on the slope 74 and upon passing, pushes portal 58 or intercepts the luminous ray 84 which generates an actuating signal to the fastener 24 of the first tow bar l4. Fastener 24, freed by the withdrawal of the stop member 20 and eventually driven by the rise of the stop member 32, releasably clamps itself automatically on the moving cable 10 by which it is driven. Meanwhile, the skier continuing to slide on slope 74 has passed the space separating him from the tow bar 14 which he has grasped while it passes (see FIG. 2). In this way, by a judicious adjustment of slope 74 and a correct positioning of the portal rod 58 relative to the tow bar in starting position, there is obtained a shockless departure of the skiers. The speed of the tow bar is predetermined so that it is substantially the same as that of the skier at the moment when the skier grasps it.

At the moment of passing the portal rod 58 or ray 84, the signal for closing the track is actuated either by the descent of the bar 64 or by the lighting of the red light 88 (see FIG. 2) thereby preventing the following skier from entering on the launching slope 74 as long as the device is not returned to its initial position ready to ensure a new launching. A timer (not shown) can delay the return of the portal or the lighting of the green light in such a way as to limit the rate of the departures and to adapt it to the traction power of cable 10. At the same time the tow bar 14 is freed by device 19, the next successive tow bar 14' is freed by device 19' which, by sliding by due to gravity on the rail 16, comes to occupy the previously isolated departure position.

It should be noted that any false maneuver is practically impossible since the first tow bar is isolated from the bunch of others. A tow bar guide (not shown) can also be employed to deviate the tow bar laterally to bring it on the trajectory of the skier who then meets it on his way.

This installation functions automatically without need of human intervention. It can easily be adapted to existing installations. The departure sequence being automatically controlled, the speed of the ski lift and consequently its flow can be substantially increased.

Naturally, the invention is not limited to the two embodiments described and shown. Various modifications, in particular different combinations of the described parts, can be restored to. The portal rod 58 could, for example, actuate the tow bar feeding device through the electromagnet 76 or a signal indicating closure of the track by signal lights. lnversely, the electrical device could comprise a track closure signal with a pivoting bar. Passage of the skier could be detected by other means, such as a turnpike or a pedal disposed on the track, and the device for releasably engaging the tow bars can be of a different type.

I claim:

1. A ski tow for towing skiers comprising: a driven cable movable along a predetermined path; a plurality of tow bars movably positioned along the path of travel of said cable, each said tow bar having thereon means actuated when said tow bar is moved to a working position for releasably engaging with said driven cable to effect movement of said tow bar with said cable; and means automatically operative in response to a skier passing a predetennined point along a skier path for individually positioning said tow bars in said working position.

2. A ski tow according to claim 1, wherein said last-mentioned means comprises detecting means for generating a signal in response to a skier passing said predetemtined point; and a tow bar feeding mechanism operative in response to said signal to feed one of said tow bars to said working position.

3. A ski tow according to claim 2, further including signal means operative in synchronization with said detecting means for providing a warning signal to other skiers during operation of said feeding mechanism.

4. A ski tow according to claim 3, wherein said detecting means comprises a pivotally mounted rod, and means mounting said rod for pivotal movement into and out of said skier path in response to a skier passing said predetermined point; and wherein said signal means comprises another pivotally mounted rod, and means mounting said another rod for pivotal movement out of and into said skier path in response to a corresponding pivotal movement of said first-mentioned rod into and out of said skier path.

5. A ski tow according to claim 4, wherein said detecting means includes a cord movable in response to pivotal movement of said first-mentioned rod; and wherein said tow bar feeding mechanism includes cord-actuated means operative in response to movement of said cord to feed one of said tow bars to said working position.

6. A ski tow according to claim 3, wherein said detecting means comprises a light source positioned on one side of said 

1. A ski tow for towing skiers comprising: a driven cable movable along a predetermined path; a plurality of tow bars movably positioned along the path of travel of said cable, each said tow bar having thereon means actuated when said tow bar is moved to a working position for releasably engaging with said driven cable to effect movement of said tow bar with said cable; and means automatically operative in response to a skier passing a predetermined point along a skier path for individually positioning said tow bars in said working position.
 2. A ski tow according to claim 1, wherein said last-mentioned means comprises detecting means for generating a signal in response to a skier passing said predetermined point; and a tow bar feeding mechanism operative in response to said signal to feed one of said tow bars to said working position.
 3. A ski tow according to claim 2, further including signal means operative in synchronization with said detecting means for providing a warning signal to other skiers during operation of said feeding mechanism.
 4. A ski tow according to claim 3, wherein said detecting means comprises a pivotally mounted rod, and means mounting said rod for pivotal movement into and out of said skier path in response to a skier passing said predetermined point; and wherein said signal means comprises another pivotally mounted rod, and means mounting said another rod for pivotal movement out of and into said skier path in response to a corresponding pivotal movement of said first-mentioned rod into and out of said skier path.
 5. A ski tow according to claim 4, wherein said detecting means includes a cord movable in response to pivotal movement of said first-mentioned rod; and wherein said tow bar feeding mechanism includes cord-actuated means operative in response to movement of said cord to feed one of said tow bars to said working position.
 6. A ski tow according to claim 3, wherein said detecting means comprises a light source positioned on one side of said skier path, and a light-responsive device positioned on the opposite side of said skier path cooperative with said light source to generate an electric signal indicative of either the presence or absence of a skier at said predetermined point; and wherein said signal means comprises at least two warning lights alternately operative in response to said signal.
 7. A ski tow according to claim 6, wherein said tow bar feeding mechanism includes an electromagnet operative in response to said electric signal to effect feeding of one of said tow bars to said working position. 